Approximately 3 million Americans and around 24 million people worldwide are affected by Type 1 Diabetes (T1D). Glucose monitoring followed by exogenous insulin injection, allogeneic whole organ pancreas transplantation, and allogeneic islet transplantation are the most common treatments for T1D. These treatments have achieved glycemic control for many patients but result in serious complications. A bioartificial pancreas is a promising treatment for T1D because it contains functional islets. Unfortunately previous attempts at BAP development have been severely limited by insufficient mass transfer within the islet chamber. The founders of Silicon Kidney have developed silicon nanopore membranes (SNM) to achieve high-efficiency blood ultrafiltration while selectively retaining specific solutes for the Bioartificial Kidney Project and this project's successes are directly transferrable to the iBAP. The ultra-high-hydraulic-permeable characteristic of the SNM will enable appropriate mass transport (especially oxygen, glucose, and insulin) within the islet chamber to achieve optimal islet performance, while the ultra-selective characteristic of the SNM enable unprecedented immunoisolation. The iBAP will be connected between an arterial and venous graft and a pressure drop across the Islet Chamber will produce an ultrafiltrate flow within the Islet Chamber. The ultrafiltrate will provide convective mass transport of nutrients (especially oxygen and glucose) to the Islet Chamber and insulin to the blood channels. The long-term objective of our project is to create the intravascular Bioartificial Pancreas (iBAP) to achieve exogenous insulin independent glycemic control of Type 1 Diabetes (T1D). This Phase I SBIR project will prove the feasibility of the iBAP by demonstrating proper Islet Chamber performance in vitro and iBAP hemocompatibility in vivo.